ii List of Figures viii List of Tables xiv Glossary of Abbreviations xv Glossary of Symbol xviii Dedication xxiv Acknowledgements xxv Declaration xxvi Chapter One Introduction 1 1.1 Background 1 1.2 Research Motivation and Justification 5 1.3 Research Objectives 11 1.4 Thesis Organisation 13 1.5 Original Contributions 15 1.6 List of Publications and Awards 18 Chapter Two Fundamentals of FSO 21 2.

Existence of line of sight (LOS) and alignment between the communicating antennas is one of the key requirements for free-space-optical (FSO) communication. To ensure uninterrupted data flow, auto-aligning transmitter and receiver modules are necessary. We previously proposed [1] a new FSO node design that uses spherical surfaces covered with transmitter and receiver modules for maintaining opt...

Maintaining optical alignment between stations of a free-space optical link requires an active pointing mechanism to persistently aim an optical beam toward the receiving station with an acceptable accuracy. This mechanism ensures delivery of maximum optical power to the receiving station in spite of the relative motion of the stations. In the active pointing scheme proposed in the present pape...

This paper illustrates the challenges imposed by the atmospheric channel on the design of a terrestrial laser communication link. The power loss due to scattering effect is described using the Kim/Kruse scattering model while the effect and the penalty imposed by atmospheric turbulence is highlighted by considering the bit error rate (BER) of an OnOff Keying modulated link in an optical Poisson...

NRL’s Chesapeake Bay lasercom test facility (LCTF) offers a variety of ranges for researching free-space optical laser communication (FSO lasercom) links in a maritime environment. This paper discusses link performance over the 16 km one-way range at the LCTF. There are several methods to determine the link quality in FSO lasercom. Bit-error-rate (BER) testing and packet testing are two possibl...

To transfer high speed data streams, a line of sight (LOS) broadband free space optical (FSO) communication link has been designed between two private local LANs located at an aerial distance of about 2 km. A laser diode (LD) – avalanche photodiode (APD) combination operating at 1550nm is used to work as an optical trans-receiver system while an Erbium-doped optical amplifier (EDFA) is used to ...

Free Space Optical (FSO) communications use modulated collimated light energy, usually in the form of an infrared (IR) laser, to transmit data. This affords FSO many appealing qualities such as a very high bandwidth capability, a high level of security through a low probability of detection (LPD) and a low probability of intercept (LPI), and a signal that is impervious to radio frequency (RF) i...

This paper presents a novel FPGA-based Gigabit Laser Ethernet Transceiver featuring a custom designed transmission protocol capable of overcoming the inherent impairments of FSO communications. The prototype is characterized and validated with a ground to ground test. OCIS codes: (060.2605) Free-space optical communications; (060.4259) Networks, packet-switched.

Free-space optical communication systems can provide high-speed, improved capacity, cost effective and easy to deploy wireless networks. Experimental investigation on the next generation free-space optical (FSO) communication system utilizing seamless connection of freespace and optical fiber links is presented. A compact antenna which utilizes a miniature fine positioning mirror (FPM) for high...

Using real-time image processing we have demonstrated a low bit-rate free-space optical communication system at a range of more than 20km with an average optical transmission power of less than 2mW. The transmitter is an autonomous one cubic inch microprocessor-controlled sensor node with a laser diode output. The receiver is a standard CCD camera with a 1-inch aperture lens, and both hardware ...